Take sildenafil at around the same times every day. Especially tell your healthcare provider if you take any of the following: medicines called nitrates medicines called guanylate cyclase stimulators such as Adempas riociguat medicines called alpha-blockers, such as Hytrin terazosin HCl , Flomax tamsulosin HCl , Cardura doxazosin mesylate , Minipress prazosin HCl , Uroxatral alfuzosin HCl , Jalyn dutasteride and tamsulosin HCl , or Rapaflo silodosin. If you experience chest pain, dizziness, or nausea during sex, seek immediate medical help. Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking sildenafil. Sildenafil for pulmonary hypertension can also be known by the brand names Revatio and Grandipam.Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum recommended dose is mg. Don’t take sildenafil (Viagra) more than once daily (at any dose). Written by Brian Leonard, PharmD, BCACP, BCGP. 16 tablets. ? / month. ? One-time or subscription. Viagra for men, often referred to as the ‘blue pill’, is an ED pill which can help to improve sexual wellbeing by enhancing erectile performance. It works by increasing blood . Sildenafil (Viagra) is used to treat erectile dysfunction (impotence; inability to get or keep an erection) in men. Sildenafil (Liqrev, Revatio) is used to improve the ability to exercise in adults (Liqrev, Revatio) and children 1 year of age and older (Revatio) with pulmonary arterial hypertension (PAH; high blood pressure in the vessels carrying blood to the .